Insulated building panels for modular construction of walls, ceilings, or the like are well known in the art. Such insulated panels are generally formed of two outer, thin-skinned metal layers of aluminum or steel having an internal, relatively thick insulating core. The concept of insulated panels has been known for many years and various types of connections have been used to connect such panels together. For example, connection was made in many such panels utilizing an additional support member, such as a cleat, to actually connect together mating edge-to-edge outer skin members of the panel in order to provide connection. In the past, efforts have been made to eliminate such cleats and to provide edge connections which are formed by the edge structure itself so that no additional cleat or other connecting member is required.
An example of such an insulated panel is found in U.S. Pat. No. 4,769,963 of Meyerson. This patent discloses insulated panels wherein one edge, the male connector, is formed of right-angled surfaces in a U-shaped configuration and the other edge, the female connector, comprises a right-angled U-shaped groove behind an inclined ramp. The core between the ramp and groove connectors has a shaped wedge core face which extends outwardly from between the ramp and groove elements. The core face between the U-shaped male connectors is cup-like in shape and is positioned inside of the U-shaped interlock elements so that when adjacent panels are snapped together, the edges or faces of the core have a tight edge-to-edge insulating seal. In order to lock together the panels of the '963 Meyerson patent using this male and female metal edge configuration, it is necessary for the panel having the male edge configuration to approach the panel having the female edge configuration at an angle so that the edge-to-edge configurations can be snapped into position. When snapped together, the U-shaped male member fits face-to-face in surface-to-surface engagement within the U-shaped groove in the female member. The interlock fit is very tight so that it is practically impossible to separate the now connected panel members by pulling them apart in the same general direction as they were put together. The only way to disconnect the panel members of the Meyerson '963 patent is to slide one panel member with respect to the other along its length, which is a very difficult and cumbersome process since the panels may be up to thirty feet long.
Another disadvantage of the panel member illustrated in the '963 patent is condensation caused by water settling on the bottom skin of the roof panel. In the situation where the panel members are connected together to form a ceiling for a room such as a patio enclosure, the upper, outer metallic skin becomes the roof and the bottom or inner metallic skin becomes the ceiling. Any leakage which travels from the top edge-to-edge connection to the bottom edge-to-edge connection actually lands and puddles on the very bottom metallic skin, which is the ceiling in the room. If the settled or accumulated liquid is cold (such as cold rain in winter) as compared to the temperature within the room, the cold liquid can cause the thin-skinned inside panel metallic skin to be reduced in temperature to the point that condensation forms on the outside of this bottom skin member (which is actually within the enclosed room). Of course, any condensation on the bottom skin member, which is the interior or ceiling side of the room, is extremely undesirable since the water may then drip onto furniture, carpet, etc. and cause the various problems caused by a leaky roof.
The same inventor, Meyerson, also has U.S. Pat. No. 5,086,599 which was evidently an attempt to eliminate some of the problems found in the panel manufactured in accordance with the '963 patent. In the '599 patent, the male portions of the edge connections include an extra wing known as a sealant press in conjunction with a smaller size male U-shaped connection member such that upon placement of the male U-shaped member in the female U-shaped groove, a space known as a sealant pocket is provided. The sealant pocket is taught as being filled with some type of sealant to prevent the passage of liquid such as rain water. The connector edge design of the '599 patent does allow the panels to be joined together while in the same plane and the panels can be taken apart the same way. One disadvantage of the design of the '599 patent relates to reliance on caulking material generally, which is undesirable since caulking or other sealant material will, over time, age, shrink, and crack and thereby begin to leak. Further, filling the U-shaped groove of the female connector with caulk eliminates a potential gutter for outward flow of rain water. Another disadvantage of the panels of both the '963 and '599 patents is that the inner core section has a nose which extends beyond the end of the metal connector and is thus exposed for potential damage.
Another type of insulated foam panel known in the art utilizes curvilinear male and female connector members to provide edge-to-edge connections. In U.K. Patent Application GB 2 168 732A, the panel disclosed includes foamed in place insulating core material and outside metal skin tongue and groove edge connectors which mate together such that the internal core of insulating material touches. In the design of GB 2 168 732A, the lug forming the male portion is a curved member where the outer edge has been curved upon itself and the female grooved connector is internally bent to form a generally rounded groove which is adapted to receive the generally rounded end of the lug edge portion thereby providing an edge-to-edge flush connection. This type of panel has a desirable feature in that the connection may be made by pushing the panels together while the panels are in the same general plane rather than having to pivot one panel into place against the other. The lug edge connector has upper and lower internal chambers. The upper chamber is said to collect any dampness which occurs in the external face so that the droplets of water run away from the bottom of the roof element due to gravity. Further the bottom recess has a sealant reservoir; however, if the seal fails and the water entering the edge connection is greater in volume than mere dampness, the water will quickly collect on the upper surface of the lower lug and overflow in the room. Another panel of similar construction is GB 2 142 670A.
The utilization of the general concept of a male edge connector on a panel to be pressed into position in a groove, recess or valley in a female edge connector in a flush fit is well known in the art, dating back at least to U.S. Pat. No. 2,682,938 of MacDonald where the internal structure is provided by wood strips rather than with an expanded insulating material.
It therefore continues to remain a challenge in the development of edge-to-edge connectors for insulated roof panels to provide insulated roof panels which may be easily installed by pushing the panels together and may be easily be taken apart, and which will avoid leaking and condensation on the interior metallic skin.
Metal to metal edge male and female configurations have been used for many years to connect together "single skin" panels. Single skin panels are single sheets of thin-skinned material such as aluminum connected together edge-to-edge to form a ceiling or wall. The use of edge-to-edge connectors for such panels is well known. Such technology is adaptable to insulated panels by inverting one connector edge configuration and then evaluating the connection made between the potentially new edge-to-edge design. However, the characteristics and advantages in an insulated panel derived from a single skin edge connector design in the instance of this invention exceeds the mere routine evaluation and experimentation.
These and other objects and advantages will become apparent from the following description.